Is it a lift pump or injectors?

[TonkaThunder]

So I was driving down the highway yesterday and all of a sudden the truck loses power. I mean I was having a hard time maintaining 35 sometimes. I did have vege oil in the tank so I figured the mix was a little thick so I stopped and topped off the tank with diesel and the truck drove fine for a few miles and I lost power again. I stopped for a couple minutes and then the truck drove great for a few minutes again. It did that the whole trip.

So today i drained most of the tank and filled it up with diesel and it ran great, more a while. The truck seems like its starving for fuel. When its acting up the injectors sound really funny and the truck will shake something fierce.

To drain the tank I just hot wired the lift pump and pumped the tank into buckets. But the lift pump didnt seem to pump consitantly. And when I reversed the pump to see if anything was stuck on the sender screen it would pump alot faster. And I have changed the fuel filter

Any help would be greatly apprectiated

[ajohansson]

If its the stock pump I say its toast. Mine lasted 8 months when I had a crappy GFS conversion. Now I run independant FASS pumps. They are awesome.

[TonkaThunder]

Thats what I was leaning towards

[TonkaThunder]

So I replaced the lift pump and no change. Is there anything else that it can be other than injectors?

[Excavator]

Can you get it scanned?
could also be UVC harness or loose poppet screw on 1 injector.
If you have valve covers off you can inspect the oil spouts for any injectors that are not spitting oil at same rate as others

Pull off oil filler cap and smell for burnt wires which is UVC

[TonkaThunder]

These are the codes P232, P1247, P1211

[MonkeyWrench]

I would try another filter, especially if you changed it before you drained the veg. oil out.

[JimTJr]

I also would try another fuel filter, since you have been running vegie,, maybe waxed up? Also, does it run absolutely TERRIBLE when down on power? Rattles, knocks, ect...? Like it's starving for fuel? Or just has no power? (But not terribly noisy from under the hood?)

Originally Posted by TonkaThunder

These are the codes P232, P1247, P1211

P0232 Fuel Pump Relay Driver Failed Off -----> This is NOT a common code, you may have a fuel pump relay going bad, and causing you intermittent fuel pump problems, which your symptoms DO sound like to me.

P1247 Turbo Boost Pressure Low ----> Boost leaks?

P1211 ICP Not Controllable - Pressure Abow/Below Desired ------> Common with a chip,,, probably nothing.

[TonkaThunder]

Honestly the original filter for all of the issues looked just fine, and this filter just looks wet. But for the power issue, it will drive just fine and make almost full power, and then all of a sudden theres just almost nothin there. It will idle at start fine, and it will actually drive city speeds pretty well. But on the highway I try and get into the throttle and the truck responds up to about half throttle and then falls on its face. And if u floor it u just hear injector tick

[calico5string]

Have you actually CHECKED the fuel pressure? It sounds like you are having a fuel supply issue. Even with a new pump, if the pick-up tube/mixer screen is partially obstructed, you will have low fuel pressure.

I would suggest you check the fuel pressure. There is a port on the rear of the fuel bowl: it is a -4 SAE/ORB thread. Screw an adapter into it, run a hose to a gauge, and read the pressure. It should be in 45-65 psi range. If the pressure is low, it may be necessary to drop the tank and check the fuel pickup for obstructions.

The P0232 code ("Fuel pump driver relay failed off") indicates that there was voltage detected on the FPM (fuel pump monitor circuit) when the fuel pump was commanded OFF. This code appeared probably because you " ...hot wired the lift pump" to empty the tank. The other two codes are most likely related to your chip. Clear them all and see if any come back.

BTW, your "lift pump" is more than just a lift pump, it is your fuel pump. It supplies the injectors directly with the required fuel pressure to operate. The term "lift pump" generally refers to a pump that gets the fuel from the tank to another pump for injection. There is no other pump (i.e. an injection pump) in the 7.3L fuel system.

Check your fuel pressure and report back...

[TonkaThunder]

Ok so I still havent gotten a chance to check fuel pressure but after a hard acceleration the truck blows a big cloud of white smoke. And the puke tank still has plenty of coolant in it

[klhansen]

Originally Posted by TonkaThunder

...but after a hard acceleration the truck blows a big cloud of white smoke.....

Sounds like fuel starvation to me.

[TonkaThunder]

So I definetly have to check fuel pressure now!

[TonkaThunder]

So I finally gave up and took the truck to a diesel mechanic and he says its either the ICP sensor or the HPOP but he will know more on monday

[Jeron]

make him check your fuel pressure. there are little screens inside the tank that will plug up and make your life a real nightmare sometimes. and also the fuel line connection on the tank really sucks. it is a quick loc fitting and the o-rings go bad and then you suck air into your fuel line also. the other thing is that the return line from the motor goes into what is called a mixing chamber inside the tank it looks like this.



notice how the return line loops around and ties into the mixing chamber then the fuel supply line sucks from that chamber also. the return usually has alot of air in it also. which can cause your injectors alot of problems over time. if you do the in tank mods it will fix all of this. and then your fuel pickup will look like this



if you do this it eliminates the little screens inside that mixing chamber so they will never clog again. you would also need to put a spin on filter on the frame before the fuel pump to protect your pump from anything that might get sucked up in the tank that the little screens used to catch.

here is a link on how to do this whole mod and what you will need to do it.

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